////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2008 Michiel Helvensteijn                                    //
//                                                                            //
// This file is part of the Mist compiler.                                    //
//                                                                            //
// The Mist compiler is free software: you can redistribute it and/or modif   //
// it under the terms of the GNU General Public License as published by       //
// the Free Software Foundation, either version 3 of the License, or          //
// (at your option) any later version.                                        //
//                                                                            //
// The Mist compiler is distributed in the hope that it will be useful,       //
// but WITHOUT ANY WARRANTY; without even the implied warranty of             //
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              //
// GNU General Public License for more details.                               //
//                                                                            //
// You should have received a copy of the GNU General Public License          //
// along with the Mist compiler.  If not, see <http://www.gnu.org/licenses/>. //
////////////////////////////////////////////////////////////////////////////////

#ifndef SINGLETON_HPP
#define SINGLETON_HPP

/******************************************************************************
 * Includes                                                                   *
 ******************************************************************************/

#include <boost/scoped_ptr.hpp>
using boost::scoped_ptr;

/******************************************************************************
 * Singleton<T> Class                                                         *
 ******************************************************************************/

template <class T>
class Singleton {
	public:
		
		static T& instance();
		
		static void destruct_instance();
	
	private:
		
		static scoped_ptr<T> _instance;
};

/******************************************************************************
 * Convenience Macro's                                                        *
 ******************************************************************************/

#define the(T) \
	Singleton<T>::instance()

#define destruct_the(T) \
	Singleton<T>::destruct_instance()

/******************************************************************************
 * Function Implementations                                                   *
 ******************************************************************************/

template <class T>
T& Singleton<T>::instance() {
	if (!Singleton<T>::_instance)
		Singleton<T>::_instance.reset(new T);
	return *Singleton<T>::_instance;
}

template <class T>
void Singleton<T>::destruct_instance() {
	Singleton<T>::_instance.reset();
}

template <class T>
scoped_ptr<T> Singleton<T>::_instance;

#endif // SINGLETON_HPP
